Mine are rock solid, I did manage to break one spoke and bend another by smashing into a rock on the fort william downhill on a hardtail, but then since I couldn't find a replacement I just carried on for another day and a half of riding including another 8 runs down the hill, and the wheels stayed in decent shape. Replaced the spokes and retrued and they're happy again. I don't hammer kit too badly usually but they've been ace, I wouldn't begrudge them a few dents but they've got absolutely none even after rolling down rocky trails with no air in the back tyre.
Anyway. Never had any issues here myself, I replaced the blue tape with yellow stans tape after I knackered it and it's, well, pretty much identical in performance. Never had a tyre slip, in fact I've hurt my thumbs removing tyres 😉 I don't use UST myself but I do have fairly tight fitting regular tyres. It's the bead of the rim that holds the tyre so that could be awkward to improve, if you use extra tape to tighten up the tyre fit you'll probably end up making the bead itself less effective.